Regulation of Energy Balance

Question 1

What percentage of energy expenditure does basal metabolic rate make up?

Answer 1

65-75%

Question 2

What are the three ways which the body expends energy?

Answer 2

basal metabolic rate, activity (both spontaneous and voluntary), thermogenesis

Question 3

What is the gold standard of measuring energy expenditure?

Answer 3

double labeled water - patient drinks water with oxygen 18 and deuterium and collect urine to look at outcomes

Question 4

What is metabolism proportionate to?

Answer 4

body size

Question 5

How is body weight maintained?

Answer 5

homeostasis - there is a set point

Question 6

Do all subjects who are force fed gain the same amount of weight?

Answer 6

No

Question 7

What correlates highly with the amount of fat gain due to force feeding?

Answer 7

activity thermogenesis (fidgeting)

Question 8

Where in the brain is weight controlled?

Answer 8

the hypothalamus

Question 9

What are the two types of neurons relating to weight in the arcuate nucleus?

Answer 9

NPY neurons and POMC neurons

Question 10

Where do neurons in the arcuate nucleus project to?

Answer 10

the paraventricular hypothalamic nucleus and the lateral hypothalamus

Question 11

What do NPY neurons secrete?

Answer 11

NPY and AGRP

Question 12

What do NPY and AGRP promote?

Answer 12

eating

Question 13

What do POMC neurons secrete?

Answer 13

MSH and CART

Question 14

What receptor does MSH bind to?

Answer 14

MC4

Question 15

What do MSH and CART inhibit?

Answer 15

food intake

Question 16

What hormones are released by the paraventricular hypothalamic nucleus?

Answer 16

oxytocin and CRH

Question 17

What do oxytocin and CRH inhibit?

Answer 17

food intake

Question 18

What hormones are released by the lateral hypothalamus?

Answer 18

orexin and MCH

Question 19

What do orexin and MCH promote?

Answer 19

food intake

Question 20

Where else does the paraventricular hypothalamic nucleus and lateral hypothalamus get input from?

Answer 20

Vagus nerve

Question 21

What modulates the system?

Answer 21

opioids, dopamine and endocannabinoids

Question 22

What else provides peripheral modulation of the system?

Answer 22

higher cortical centres (conscious will), the size of fat stores and the presence of food in the gut

Question 23

What is leptin?

Answer 23

A peptide hormone made in fat cells in proportion to the size of the cell that travels to the brain and is a powerful inhibitor of food intake

Question 24

What is insulin?

Answer 24

A peripheral signal that is a long term inhibitor of food intake

Question 25

How are nutrients involved in food intake control?

Answer 25

Can inhibit food intake

Question 26

How does glucose inhibit food intake?

Answer 26

glucose metabolism leads to the production of malonyl-CoA which inhibits CPT1 preventing the breakdown of LCFA-CoA which inhibits food intake

Question 27

What genes determine obesity?

Answer 27

leptin, leptin receptor, POMC, prohormone covertase 1, MC4R

Question 28

What explains the increase in prevalence of obesity?

Answer 28

epigenitics

Question 29

What are causes of spontaneous weight loss?

Answer 29

endocrine diseases, gastrointestinal diseases, infection, malignancy, anorexia nervosa